Power reserve indicator



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POWER RESERVE INDICATOR I Maxime Favret, Elgin, 111., assignor to Elgin National Watch Company, Elgin, 11]., a corporation of Illinois Application July 18, 1952, Serial No. 299,708

8 Claims. (Cl. 185-44) This invention relates to an indicator for the amount of energy or power stored in a device such asthe spring of a spring motor; and is illustratively shown in connection with a spring-driven horological instrument.

A feature of the invention is the provision of parts actuated from the input and output ends of a power storage device and operative to move an indicator.

Another feature is the provision of parts connected with a power-storing spring which is wound from one end and delivers its energy at the other, and including a differentiating element and an indicator driven thereby.

A further feature is the provision of an indicator and parts for actuating the same and connected with a power storing spring which is wound from one end and delivers its energy at the other and including a slippage device, said parts including a differentiating element including slippage means whereby over-winding of the spring, with slippage therein, is accompanied by slippage in the indicating parts.

With these and other features as objects in view, illustrative forms of practice of the invention, in association with a watch, are shown in the accompanying drawings, in which:

Figure l is a plan of one form of the device, seen from the dial side of the watch movement, with parts of the dial and of the pillar plate broken away.

Figure 2 is a section substantially on the broken line 22 of Figure 1.

Figure 3 shows a modified form, corresponding to parts of Figure 2.

Figure 4 shows another form, corresponding to parts of Figure 2, with a separate indicator moving about a pivot.

Figure 5 shows a further form, corresponding to parts in Figure 4, with the indicator located at the center of the dial.

Figure 6 shows a further form, corresponding to parts in Figure 2, with the indicator mounted concentrically with the differentiating system.

In these drawings, the invention is illustrated as applied to a watch having a front plate or dial D, hands sleeve and stafi assembly HM, a pillar plate PP, a spring barrel B with main spring S therein, and a spring arbor A. These parts may be constructed in presently known ways, and connected with other watch parts (not shown), such as bridges, trains, balance and escape structures, dial feet and the like.

The spring barrel B has fixed thereto a pinion 10 which moves loosely about the arbor A. The arbor A has a pinion 11 fixed thereto. The pinions 10, 11 may have twelve teeth.

The pillar plate PP is formed with a recess 12 beneath the dial D, and supports a stud or bearing post 13 extending toward the dial. A first gear 15 is rotatable about the axis of this post and has a central hollow flange 16. A plate 17 is rotatable about the flange 16 and has holes therethrough for receiving differentiating members such as the illustrative three balls 18 in Figures 1 and 2. A second gear 20 also is rotatable about the flange 16. A dished spring washer 22 is mounted on the flange 16, which may be made with a shoulder to receive the washer 22 and have its end swaged or staked to maintain the assembly so that the parts are held together and a light friction is established to restrict and steady their relative movements.

The plate 17 carries an indicator pin 24 which is visible through the arcuate slot 25 in the dial.

United States Patent O ice ' The pillar plate PP supports a stud 26, directed away from the dial D, upon which is loosely rotatable an idler 27.

The arbor pinion 11 is in mesh with the second gear 20; and the barrel pinion 10 is in mesh with the idler 27 which in turn is in mesh with the first gear 15.

Winding is accomplished by rotating the idler 30 by usual means such as a self winding' weight W on arm A with a pawl P to move the center drive pinion, X in mesh with the idler 30; these parts being conventionalized; with employment of'a click or retaining pawl 31. As the idler 30 turns, it causes the pinion 11 and therewith the arbor A to rotate, thus winding the spring within the going barrel, which is shown with the teeth 32 for driving the watch train (not shown): the arbor A turns counterclockwise in the illustrative form. The pinion 11 also causes the second gear 20 to rotate clockwise in Figure 1: and this gear causes the balls 18 to rotate and therewith travel in a circular path upon the first gear 15: these balls 18 push the plate 17 in clockwise direction so that it moves by one-half of the travel of gear 20 relative to gear 15, and carries the indicator 24 along the slot 25 in the dial D. This slot, by original design of the dial and the ratios of pinions 10, 11 to gears 20, 15 has the indicator 24 at the dotted line position 2411 when thespring has run down, i. e. when the spring has delivered its available energy. As winding occurs the indicator 24 moves toward the full line position in Figure l which it attains when the spring has been half-wound: and then continues until it finally occupies the dotted line position 24a when the spring is fully wound.

The spring S drivesthe watch train and escapement, by actuating thebarrel B and causing it to move counterclockwise in Figure l, wherewith the pinion. 10 turns the idler clockwise, and in turn the first gear 15 is driven counterclockwise and therewith likewise causes the balls 18 to roll and travel, so that they push the plate 17in a counterclockwise direction, opposite to the winding movement, andtherewith the indicator is carried back from fully wound position 24a to the unwound position 2 4b, indicating at all times at the slot 25 the power reserve which exists. l g

It will be noted that the gears 15, 20 and balls 18 withplate 17 provide a difierentiating device which is effective regardless of the positions occupied by either of the gears 15, 20, and also being etiective even though winding is accomplished slowly while the spring is concurrently acting to drive the train and escapement. The 2:1 reduction in movement of the indicator permits gear ratios of customary type to be used, without demanding an excessive length for the slot 25: and is accomplished independently of the diameters of the balls 18, the radial distance from the axis of post 13, or the diameters of the gears 15, 20.

The described structure also has a self-adjusting effect upon first winding, and during subsequent windings, by reason of the slippage between balls 18 and one or both gears 15, 20. Thus, the parts can be assembled with the spring unwound and with the indicator 24 in any position in the arcuate slot 25. When the watch is then fully wound, the indicator is carried to the position 24a and, if further winding of the spring is possible, this occurs while the gear 20 slips relative to the plate 17 while the plate is being detained by the engagement of the indicator 24 with the end of the slot. Thereafter, in unwinding, the action is as before. This slippage also occurs if the spring and barrel have frictional engagement to prevent damage by overwinding, through relative slippage therebetween: at full winding the indicator 24 is held by the end of the slot, and any excessive winding motion has no effect upon its position.

In the modified form of Figure 3, the index or pointer 34 is mounted on the indicator pin 24.

In the form of Figure 4, the plate 17a has a toothed edge for meshing engagement with a toothed sector 40 carried by a rotatable pin 41, which is pivoted in the pillar plate 'PP and in a steadying bridge piece 42, and projects through a circular hole 43 in the dial D for supporting an index 44. This form is advantageous when a circular 0 hole rather than a slot is desired in the dial.

In Figure 5, the parts are connected and operate as with Figure 4;but the sector 40 is carried by a sleeve 46 which surrounds the hour sleeve, and the index 44 thus moves concentrically with the hour-and minute hands.

In Figure 6, the gears 15, 20, plate 17, and differentiatingelements -18,are present as before. :In this forrn, :the staff s!) is fixeddothe plate 317 and .is pivoted in the pillar plate PP and an indicator bridge 51 mounted on the pillar plate. The gears :15, 20cm turn aboutthe staff 50, .but friction is maintained between the parts by ,the dished washer 22 which reacts agairst the bridge '51. The staff 50 extends through ,the ,dial D and carries an index ,54. This form is advantageous .when the staff '50 can be mounted at a :position in which the index 54 can move overa desirable part of the dial.

In Figure-,6, the differentiating elements 18-are shown asrrollers; and these will be understood :to be a general equivalent of balls.

A technical advantage exists in the form of Figure 2, inthat a sub-assembly of the gear 15, plate 17, gear 20 and washer 22, with the differentiating elements 18 in place, may beseparately made, and furnished to the watch assembler for final installation. This also permits more facile cleaning of the mechanism and its replacementand repa r.

in the illustrative form in Figure 2, the gears 15, 20 have-surface grooves in which the differentiating elements 18 travel; which is advantageous in reducing the overall thickness of this sub-assembly for given diameters of elements 18 andthicknesses of the gears 15, 20.

The illustrative forms are given by way of examples and it will be understood that they are not restrictive, and thatother forms may :be employed within the scope of the appended claims.

I claim:

1. A powerreserve'indicator for a spring, comprising a pair of concentric gears, means connected to the ends of thespring for rotating said gears in opposite directions, a movable plate between the gears, rolling elements mounted in theplate and frictionally contacting end surfaces -of both said gears whereby the plate is caused to move as the said'elements roll on said gears during relatilve rotation of said gears, and an index operated by said p ate.

2. Apower reserve indicator for a spring, comprising a pair oftconcentric gears, means connected tothe endsof the spring for rotating said gears in opposite directions, a movable plate between the gears, balls mounted in holes in theplate and contacting both said gears, a spring effecfive to urge said gears toward one another, and an index operated .by said plate.

3. A power reserve indicator for a spring mounted in a barrel and connected to-a central arbor, comprising pinions on said barrel and arbor, an idler, a pair of concentric gears, one gear being in mesh with one pinion, the other gear being in mesh with the idler and the idler in mesh with the other pinion, a movable plate between the gears, balls mountedin holesin theplate and contacting both said gears, and an index operated by said plate.

v4. A power-reserve indicator as in claim 1, in which theparts are mountedon afixed structure including a front plate having an arcuate slot, said plate being pivoted concentric to theslot withthe index extending through the slot, whereby the ends of the slot are effective to limit the movement of the index.

5. A power reserve indicator as in claim 1, in which the parts are mounted on a fixed structure including a front plate, and said movable plate has teeth,.a tooth'sector on a staff pivoted on saidstructure, said staff extending through the front plate .for supporting a visible index, said teeth being in meshing relation to said sector.

6. A power reserve indicator as in ,claim 1, in which the movable plate is fixed to a staff, and said staff carries the index.

7. A power reserve indicator as in claim 1, in which one said gear has a. centralflange, and said movable plate and. the-other gear are rotatablymountedon said flange, and a springsurrounding and secured to the flange adjacent its free. end, said spring bearing upon the other gear for imposing friction upon the relatively movable gears.

-8. A power reserve indicator for a spring, comprising a pair of, concentric members, meansconnectedto the ends ofthe springfor rotating said members in opposite directions, a movable plate between the members, rolling ele ments mounted in the plate, and frictionally contacting end surfaces of both said members, an indexoperated by theplate, anda spring effective for pressing the members togetherandmaintaining said frictional contact.

References Citedin the file of this patent UNITED-STATES PATENTS Number 7 Name Date 1,302,539 Gullborg May 6, 1919 1,473,929 Freedman Nov. 13, 1923 2,443,558 Frennesen June 15, 1948 

